DISEASE: Bacterial blast
HOST: Pear
The bacterium infects all flower parts and may spread and kill the entire spur.

Bacterial blast | Pear
DISEASE: Bacterial blast
HOST: Pear (Pyrus communis)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: W. Sinclair
DISEASE: Bacterial dieback of nectarine
HOST: Nectarine
Fruit lesions is another symptom of this disease.

Bacterial dieback of nectarine | Nectarine
DISEASE: Bacterial dieback of nectarine
HOST: Nectarine (Prunus persica var. nucipersica 'Redgold')
PATHOGEN: Pseudomonas syringae pv. persicae
SOURCE: J. Young
DISEASE: Bacterial spot
HOST: Nectarine
Nectarine with necrotic spots on leaves and dark necrotic spots on fruit.

Bacterial spot | Nectarine
DISEASE: Bacterial spot
HOST: Nectarine (Prunus persica var. nucipersica 'Redgold')
PATHOGEN: Xanthomonas arboricola pv. pruni
PATHOGEN SYNONYM: Xanthomonas campestris pv. pruni
SOURCE: J. Young
DISEASE: Bacterial wilt
HOST: Squash
Field with severe symptoms of wilt. Foliage often is chlorotic and leaf margins may be chlorotic and necrotic before plant death. Bacterial ooze may be seen streaming from the xylem when infected stems are cut.

Bacterial wilt | Squash
DISEASE: Bacterial wilt
HOST: Squash (Cucurbita maxima)
PATHOGEN: Erwinia tracheiphila
SOURCE: B. Jacobsen, M. Shurtleff
DISEASE: Crown gall
HOST: Pear
Crown gall of pear rootstock.

Crown gall | Pear
DISEASE: Crown gall
HOST: Pear (Pyrus communis)
PATHOGEN: Agrobacterium tumefaciens
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: H. Sawada, M. Goto
DISEASE: Fire blight
HOST: Pear
Blighted shoot and blossoms.

Fire blight | Pear
DISEASE: Fire blight
HOST: Pear (Pyrus communis)
PATHOGEN: Erwinia amylovora
SOURCE: M. Schroth
DISEASE: Fire blight
HOST: Pear
Typical appearance of advanced stage of disease after the bacterium invades from shoot tips/flowers downward.

Fire blight | Pear
DISEASE: Fire blight
HOST: Pear (Pyrus communis)
PATHOGEN: Erwinia amylovora
SOURCE: M. Schroth
DISEASE: Fire blight
HOST: Pear
The disease causes lack of leaf detachment on infected branches, commonly seen during California winters.

Fire blight | Pear
DISEASE: Fire blight
HOST: Pear (Pyrus communis)
PATHOGEN: Erwinia amylovora
SOURCE: M. Schroth